Journal Club Alcohol, Other Drugs, and Health: Current Evidence July–August 2009 www.aodhealth.org Featured Article Alcohol Use and Risk of Pancreatic Cancer: The NIH-AARP Diet and Health Study Jiao.
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Transcript Journal Club Alcohol, Other Drugs, and Health: Current Evidence July–August 2009 www.aodhealth.org Featured Article Alcohol Use and Risk of Pancreatic Cancer: The NIH-AARP Diet and Health Study Jiao.
Journal Club
Alcohol, Other Drugs, and Health: Current Evidence
July–August 2009
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1
Featured Article
Alcohol Use and Risk of
Pancreatic Cancer:
The NIH-AARP Diet and
Health Study
Jiao L, et al. Am J Epidemiol. 2009;169(9):1043–1051.
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Study Objective
• To determine the relationship between
alcohol use and risk of pancreatic cancer.
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Study Design
• Prospective cohort of 470,681 participants
from the US National Institutes of Health
(NIH)-AARP Diet and Health Study who were
aged 50–71 years between 1995–1996.
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Assessing Validity of an
Article About Harm
• Are the results valid?
• What are the results?
• How can I apply the results to
patient care?
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Are the Results Valid?
• Did the investigators demonstrate similarity in all
known determinants of outcomes? Did they
adjust for differences in the analysis?
• Were exposed patients equally likely to be
identified in the two groups?
• Were the outcomes measured in the same way in
the groups being compared?
• Was follow-up sufficiently complete?
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Did the investigators demonstrate similarity in
all known determinants of outcomes? Did they
adjust for differences in the analysis?
• Yes.
– The analysis used multivariable Cox proportional
hazards regression models to adjust for major
potential confounders. The final models were
adjusted for gender; smoking history; daily energy
(k/cal), saturated fat, red meat, and folate intake;
body mass index; physical activity; and self-reported
history of diabetes.
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Were exposed patients equally likely
to be identified in the groups?
Yes.
– All participants were prospectively queried about
alcohol use for the 12 months prior to baseline;
therefore, there should be no differential
ascertainment of alcohol exposure.
– The exposure was presumed to be static, and
those who reported no alcohol consumption may
have included former drinkers.
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Were the outcomes measured in the
same way in the groups being compared?
Subjects were contacted on a regular basis
as part of the observational study, but there
were no procedures for active surveillance
of pancreatic cancer.
Incident pancreatic cancer outcomes were
determined through state cancer registries.
Fatal cases were determined through
linkage with the National Death Index.
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Was follow-up sufficiently complete?
• Approximately 4% of participants were lost
to follow-up.
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What are the Results?
• How strong is the association between
exposure and outcomes?
• How precise is the estimate of the risk?
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How strong is the association between
exposure and outcome?
How precise is the estimate of the risk?
• Beverage-specific effects revealed no increase in
risk for consumers of any amounts of beer or wine
or for consumers of liquor up to 3 drinks per day.
• Compared with light drinkers, the RR of
developing pancreatic cancer was
– 1.45 (95% confidence interval (CI): 1.17, 1.80) in subjects
who drank ≥3 drinks of beer or wine per day;
– 1.62 (95% CI: 1.24, 2.10) in subjects who drank ≥3
drinks of liquor per day; and
– 1.41 (95% CI: 1.01, 2.00) in subjects who had quit
smoking 10 or more years earlier.
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How Can I Apply the Results to
Patient Care?
• Were the study patients similar to the patients
in my practice?
• Was the duration of follow-up adequate?
• What was the magnitude of the risk?
• Should I attempt to stop the exposure?
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Were the study patients similar to the
patients in my practice?
• The sample included 470,681 men and women
aged 50–71 years from 6 US states (California,
Florida, Louisiana, New Jersey, North Carolina,
and Pennsylvania and 2 US metropolitan areas
(Atlanta and Detroit).
• Patients with cancer or extreme dietary intake
(>2 interquartile ranges above the 75th or
below the 25th percentile of Box-Cox logtransformed energy intake) were excluded.
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Was the duration of follow-up adequate?
• Average follow-up time was 7.3 years, which may
not be long enough to establish a strict causal
relationship unless one assumes that baseline
drinking approximates adult lifetime alcohol
exposure.
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What was the magnitude of the risk?
• Consuming >3 drinks of alcohol or liquor per
day was associated with an approximately
50% increase in risk for pancreatic cancer.
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Should I attempt to stop the exposure?
• The potential additive risk should be
discussed with individuals in light of other
known risk factors for pancreatic cancer
including tobacco use, diet, and high caloric
intake.
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